Totani Masayasu, Tanihata Yuko, Egi Yusuke, Kadokawa Jun-Ichi
Graduate School of Science and Engineering, Kagoshima University, 1-21-40 Korimoto, Kagoshima 890-0065, Japan.
Graduate School of Science and Engineering, Kagoshima University, 1-21-40 Korimoto, Kagoshima 890-0065, Japan.
Int J Biol Macromol. 2025 Jan;286:138441. doi: 10.1016/j.ijbiomac.2024.138441. Epub 2024 Dec 5.
In this study, all-chitin composite films, named self-rein orced chitin composite (SR-ChC) films, were fabricated from aqueous acetic acid dispersions of highly-crystalline scaled-down chitin nanofibers (SD-ChNFs, crystalline index (CI) = 90.5 %) and scaled-down low-crystalline chitin (SD-LC-Ch, CI =57.4 %) powder. A SD-ChNF dispersion with aqueous acetic acid was obtained by regeneration from a chitin ion gel and subsequent disintegration of the resulting ChNFs. Separately, the SD-LC-Ch powder was prepared by treating chitin powder under alkaline conditions and subsequent additional deacetylation, which showed well-dispersibility in aqueous acetic acid. The two dispersions were mixed, followed by suction filtration and drying, to obtain the SR-ChC films. The composite films were characterized by scanning electron microscopic, powder X-ray diffraction, and tensile testing measurements. As weight ratios of the SD-LC-Chs increased, the components gradually embedded the SD-ChNFs, allowing reduction of the crystallinity of the SR-ChC films (CIs = ∼ 63.4 %). The tensile testing revealed that the SR-ChC film with the SD-LC-Ch/SD-ChNF weight ratio of 6.6/1 exhibited superior mechanical properties, including tensile strength of 64.0 MPa, elongation of 22.4 % at break, Young's modulus of 0.924 GPa, and toughness of 1109 J m. The mechanism for the improvement of properties was also discussed.
在本研究中，全甲壳素复合薄膜，即自增强甲壳素复合（SR-ChC）薄膜，由高结晶度的缩小小径甲壳素纳米纤维（SD-ChNFs，结晶指数（CI）=90.5%）和缩小小径低结晶度甲壳素（SD-LC-Ch，CI =57.4%）粉末的醋酸水溶液分散体制备而成。通过从甲壳素离子凝胶再生并随后将所得的ChNFs分解，获得了醋酸水溶液中的SD-ChNF分散体。另外，通过在碱性条件下处理甲壳素粉末并随后进行额外的脱乙酰化来制备SD-LC-Ch粉末，其在醋酸水溶液中表现出良好的分散性。将两种分散体混合，然后进行抽滤和干燥，以获得SR-ChC薄膜。通过扫描电子显微镜、粉末X射线衍射和拉伸测试测量对复合薄膜进行了表征。随着SD-LC-Chs重量比的增加，这些组分逐渐嵌入SD-ChNFs中，从而使SR-ChC薄膜的结晶度降低（CIs = ∼ 63.4%）。拉伸测试表明，SD-LC-Ch/SD-ChNF重量比为6.6/1的SR-ChC薄膜表现出优异的机械性能，包括拉伸强度为64.0 MPa、断裂伸长率为22.4%、杨氏模量为0.924 GPa以及韧性为1109 J m。还讨论了性能改善的机制。
